condensation in workshop

Yo! I am insulating a part of my barn's top floor to be able to use my woodworking tools occasionally during the winter. I will use a 220v 4800w heater for the few hours I need to work there. In between uses, would it be better to let the outside air flow freely through by opening a few panels under the roof's edge? I noticed that my lathe and other tools downstairs in the post and beam section tend to gather condensation on hot, damp summer days. Not a spec of rust on the second floor where air penetrates freely under the tin roof edges, over the top beam. No temperature differences, I guess. Opening and closing would be easy as I'm only putting in 2-layered bubble insulation with aluminium backing. Warm thoughts from Up North...

one thing you can try. my uncle had a damp basement where we grew up and he used to hang burlap bags of halite salt from the cieling and let it drip into buckets around the basement. I don't know why it does it but the salt is always cooler then the air around it and it attracts the moisture out of the air.